The aim of this project is to examine how wound induced v-Ha-ras transgene expression modulates the expression of genes known to regulate skin cell differentiation during normal wound repair. Full thickness wounding mimics TPA promotion by inducing papillomas along the wound line of TG.AC skin. We also know, without exception, that all wound induced papillomas in TG.AC express the v-HA-ras transgene. Recent studies have shown that Bcl-2/Bax, and TGF-a/TGF-b modulate skin cell differentiation pathways during wound repair. In addition to these studies, we have preliminary evidence demonstrating aberrant expression of these genes in TPA/wound promoted TG.AC skin. Therefore, we believe that wound promotion is a perfect experimental system to study how mutant Ras expression (signal transduction) perturbs the normal expression of key wound repair genes in TG.AC mouse skin. This study will utilize in situ hybridization, rt-pcr and RNA blot assays to determine location and relative changes of key wound repair genes in TG.AC temporal wound repair. We have performed a temporal study of wound healing in TG.AC and the isogenic parental FVB/N strain. All tissues have been collected, fixed and frozen. Probes for in situ and RNA blot experiments are available. In situ hybridization and pcr experiments are underway.